Role of Troponins I and T and N-Terminal Prohormone of Brain Natriuretic Peptide in Monitoring Cardiac Safety of Patients With Early-Stage Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer Receiving Trastuzumab: A Herceptin Adjuvant Study Cardiac Marker Substudy

Arginine-Nitric Oxide Metabolites and Cardiac Dysfunction in Patients With Breast Cancer

BACKGROUND

Oxidative/nitrosative stress and endothelial dysfunction are hypothesized to be central to cancer therapeutics-related cardiac dysfunction (CTRCD). However, the relationship between circulating arginine-nitric oxide (NO) metabolites and CTRCD remains unstudied.

OBJECTIVES

This study sought to examine the relationship between arginine-NO metabolites and CTRCD in a prospective cohort of 170 breast cancer patients treated with doxorubicin with or without trastuzumab.

METHODS

Plasma levels of arginine, citrulline, ornithine, asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), and N-monomethylarginine (MMA) were quantified at baseline, 1 month, and 2 months after doxorubicin initiation. Determinants of baseline biomarker levels were identified using multivariable linear regression, and Cox regression defined the association between baseline levels and 1- or 2-month biomarker changes and CTRCD rate in 139 participants with quantitated echocardiograms at all time points.

RESULTS

Age, hypertension, body mass index, and African-American race were independently associated with ≥1 of baseline citrulline, ADMA, SDMA, and MMA levels. Decreases in arginine and citrulline and increases in ADMA were observed at 1 and 2 months (all p < 0.05). Overall, 32 participants experienced CTRCD over a maximum follow-up of 5.4 years. Hazard ratios for ADMA and MMA at 2 months were 3.33 (95% confidence interval [CI]: 1.12 to 9.96) and 2.70 (95% CI: 1.35 to 5.41), respectively, and 0.78 (95% CI: 0.64 to 0.97) for arginine at 1 month.

CONCLUSIONS

In breast cancer patients undergoing doxorubicin therapy, early alterations in arginine-NO metabolite levels occurred, and early biomarker changes were associated with a greater CTRCD rate. Our findings highlight the potential mechanistic and translational relevance of this pathway to CTRCD.

Developing a Comprehensive Cardio-Oncology Program at a Cancer Institute: The Moffitt Cancer Center Experience

Cardio-oncology is a multidisciplinary field focusing on the management and prevention of cardiovascular complications in cancer patients and survivors. While the initial focus of this specialty was on heart failure associated with anthracycline use, novel anticancer agents are increasingly utilized and are associated with many other cardiotoxicities including hypertension, arrhythmias and vascular disease. Since its inception, the field has developed at a rapid pace with the establishment of programs at many major academic institutions and community practices. Given the complexities of this patient population, it is important for providers to possess knowledge of not only cardiovascular disease but also cancer subtypes and their specific therapeutics. Developing a cardio-oncology program at a stand-alone cancer center can present unique opportunities and challenges when compared to those affiliated with other institutions including resource allocation, cardiovascular testing availability and provider education. In this review, we present our experiences establishing the cardio-oncology program at Moffitt Cancer Center and provide guidance to those individuals interested in developing a program at a similar independent cancer institution.

Cardiac safety, efficacy, and correlation of serial serum HER2-extracellular domain shed antigen measurement with the outcome of the combined trastuzumab plus CMF in women with HER2-positive metastatic breast cancer: results from the EORTC 10995 phase II study

PURPOSE

Cardiotoxicity is a side effect of trastuzumab. We assessed efficacy and cardiac safety of CMF with trastuzumab (CMF+T) in HER2-positive metastatic breast cancer patients (MBC).

METHODS

In this phase II study, centrally confirmed, previously treated HER2-positive MBC patients with measurable disease (per RECIST v 1.0) were enrolled. Initially, patients were randomized between 8 CMF cycles alone or combined with trastuzumab during chemotherapy, followed by 3-weekly trastuzumab maintenance till progression. A protocol amendment dropped the CMF arm and thereafter all patients received CMF+T. Translational research for prediction of treatment benefit was performed through serial serum HER2-shed antigen assessments.

RESULTS

Ninety patients (CMF: 19; CMF+T: 71) were enrolled between 2002 and 2006. Median age was 54 years. 42 patients had prior chemotherapy (33 with anthracyclines) and 41/71 patients who received CMF+T continued trastuzumab monotherapy for a median duration of 40 weeks. Overall response rate was 50% for CMF+T (35/70) and 32% for CMF (6/19). Median duration of response was 10.3 months and 5.4 months, respectively. Median progression-free survival was 9.4 months (95% CI 8.1-11.6) and 4.8 months (95% CI 2.8-7.9), respectively. In the CMF+T arm, 13(18%) patients had an absolute LVEF decline, including 3 patients developing any grade of New York Heart Association cardiac dysfunction. Patients with an increase of 30% over baseline shed antigen had a higher progression risk (95% CI 7.6, 3.9-14.8).

CONCLUSIONS

CMF+T is effective, with an acceptable cardiotoxicity profile. LVEF declines were mostly asymptomatic and occurred irrespective of previous anthracycline exposure. CMF+T can be considered for these patients, if other cytotoxics are contraindicated.